Malicious PDF — malware analysis report

Static analysis result for SHA-256 35905672b4d7cf9c…

MALICIOUS

PDF

88.9 KB Created: 2021-07-26 12:07:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 4715b2dd253ffc0b3c23c20960681dd3 SHA-1: 93308b30489a795cc2bcb905cdfc23ab6caa240e SHA-256: 35905672b4d7cf9c961cb4063e7c16788481a19382e65e7aef97c28e0dffe133
204 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains multiple heuristics indicating malicious intent, including links to algorithmically-generated URLs and compromised CMS upload storage. The presence of a visual download button suggests a social engineering lure. ClamAV detection as 'Pdf.Phishing.Trojan' further supports the malicious classification. The document's primary function appears to be directing users to download a secondary malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://fietenhaardenenkachels.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16083e0d748877---nafufamizakelibafi.pdf In PDF document text
    • http://www.gunyagder.org.tr/wp-content/plugins/super-forms/uploads/php/files/4sl8kqmlaopnd9miscpaqp1nd1/zavifesag.pdfIn PDF document text
    • http://beerskiboot.com/img/upload/file/rabuk.pdfIn PDF document text
    • https://accuratesearch.com/userfiles/file/33840417579.pdfIn PDF document text
    • http://kovove-ploty-brany-zabradli.cz/UserFiles/File/71293562123.pdfIn PDF document text
    • http://whippets-au.com/clients/7/7f/7f5032e15db821a993a8146895416847/File/botusirosanixadesep.pdfIn PDF document text
    • http://almar-bus.pl/userfiles/file/zekofasolobekopomubif.pdfIn PDF document text
    • https://kodeac.com/wp-content/plugins/super-forms/uploads/php/files/uf38a82d2ajsnciglep68jjavn/sejiwinupuboniguf.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606e47566ebc7---28503221187.pdfIn PDF document text
    • https://edoxmarketing.com/wp-content/plugins/super-forms/uploads/php/files/d09ml5938b3fmgadnrr55dsu2g/vonijemurevabumajaj.pdfIn PDF document text
    • https://agatanorek.com/files/file/gotovedewin.pdfIn PDF document text
    • http://akkoryazilim.com/userfiles/file/gamajonekek.pdfIn PDF document text
    • http://developmentassociationofnagaland.org/nbloom/fckuploads/file/fisubejefamemiwaturubujal.pdfIn PDF document text
    • http://guss-ex.de/uploads/fck/file/famuveneviwip.pdfIn PDF document text
    • http://cioccolatogallucci.it/userfiles/file/23271140904.pdfIn PDF document text
    • http://asiancfea.org/userfiles/file/31498547035.pdfIn PDF document text
    • https://dmddsgn.com/wp-content/plugins/super-forms/uploads/php/files/efd2ecd589221d1faa95375fbf988903/19296925855.pdfIn PDF document text
    • https://revapackers.com/wp-content/plugins/super-forms/uploads/php/files/ht367r7hje7led2odblonhm8ba/27933475268.pdfIn PDF document text
    • https://nobleanimalsanctuary.org/wp-content/plugins/super-forms/uploads/php/files/tmp/mimixotixumilepagowekuk.pdfIn PDF document text
    • https://strategieb2b.com/userfiles/file/jemimux.pdfIn PDF document text
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/160e982772532d---7240302043.pdfIn PDF document text
    • http://www.tenniscanberra.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16094690ed48b7---tupiduf.pdfIn PDF document text
    • https://www.sblending.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1609d081fdd4c2---41008533026.pdfIn PDF document text
    • https://hacunamatata.ru/wp-content/plugins/super-forms/uploads/php/files/7d853a61b867c195d74e41a37c147690/17494936530.pdfIn PDF document text
    • https://banghenails.com/upload/file/durevepozesa.pdfIn PDF document text
    • https://defi128.com/userfiles/files/62927676132.pdfIn PDF document text
    • http://moveisgarciadigital.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c6fc778739f---47485701407.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=how+to+calculate+depreciation+on+fixed+assets+in+excelPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f437.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF437 10892 bytes
SHA-256: 57065e97ccebc59e932ee0b6fce31781bc1ecb47980089298e1c540f18295c4d
font_01_sfnt_off00010d8e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D8E 17636 bytes
SHA-256: 30c99d03380aa674e314dc6be001bd2c24b809b1267d3ce8eebbe7d85ddb03b7
font_02_sfnt_off00013c31.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C31 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1