Malicious PDF — malware analysis report

Static analysis result for SHA-256 91c19ff7d03132b9…

MALICIOUS

PDF

82.0 KB Created: 2021-07-02 17:53:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0123e1817988de87e1cc8d04474c326a SHA-1: 09a15e6ba83345b719a95001efdfe141fb0e7914 SHA-256: 91c19ff7d03132b9b18243317e5173e33db742dc6eeff6a0b0ce994400a5b0c5
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a phishing or trojan threat. It contains numerous embedded URLs pointing to compromised WordPress sites and disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of these links and the overall structure strongly indicate an attempt to lure users to external sites for further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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.
  • 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://nomylo.ru/uplcv?utm_term=types+of+structured+poems
    • https://ekransamara.ru/files/ravufodusowikefuxonul.pdf
    • http://79.170.40.182/boothtastic.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608423ecc79e1---gorezo.pdf
    • http://chikatere.com/Upload/files/jedobofadajisokorudoxos.pdf
    • http://gsxr.hu/userfiles/file/57473372225.pdf
    • https://www.blackandwhite-salon.com/wp-content/plugins/super-forms/uploads/php/files/3711c2ca0eb1e78b85ea33cc59d36e04/7163801381.pdf
    • http://princeverma.in/uploads/files/15016808998.pdf
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1606c9ab874654---2146337779.pdf
    • https://growlocals.com/wp-content/plugins/super-forms/uploads/php/files/f353f0c631ccdf972b051de131bdae86/zukimidobovodopase.pdf
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606d0135be1aa---zaxewo.pdf
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/39dec6252123ed0024de3a664b4202ff/mikopukurezikerodetuz.pdf
    • https://traveltokiev.com/wp-content/plugins/super-forms/uploads/php/files/0pqdo30jfn4kbtlgab9nonnb41/75284141854.pdf
    • http://doo-san.com/userfiles/file/20210518172948.pdf
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/9t7a8q0c0gosa5pq4se83hnuf4/kinegukividoxejapo.pdf
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609c51b214f23---buvunoxagosawidenit.pdf
    • http://www.mywil.ch/wp-content/plugins/formcraft/file-upload/server/content/files/16077c912d9118---toxedo.pdf
    • http://wecans.net/_UploadFile/Images/file/leroxugidepumulenumeguzet.pdf
    • http://amako-ra.com/wp-content/plugins/super-forms/uploads/php/files/775e9e896ec47a03924b57645fe3d884/96608775237.pdf
    • https://xn----8sbaavnccwq4am.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/9f23f809f0cbe9ed20279eb84b10cbea/lowoto.pdf
    • http://garderoba.sk/images/_file/83513135572.pdf
    • http://almar-bus.pl/userfiles/file/16899690859.pdf
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b01e4611b7---45018347493.pdf
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/1606efb2e96a61---polutoduvipupexoxovopewe.pdf
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/1609cc28f7c127---bezusejubutuvufufed.pdf
    • http://www.sport-konyv.hu/userfiles/file/46825733615.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000de03.bin
6c1ba2861bad8faaba3d120d04caa8ed0c608cfe1e2bc6f709a6a34ac4029b13
pdf-font-stream PDF embedded font (sfnt) at offset 0xDE03 10552 bytes
font_01_sfnt_off0000f62c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF62C 16792 bytes
font_02_sfnt_off00010e3e.bin
fed2b976ce718957490aa1b746427f5827bd388ab302b01c3f747c0bc3feb91d
pdf-font-stream PDF embedded font (sfnt) at offset 0x10E3E 17112 bytes