Malicious PDF — malware analysis report

Static analysis result for SHA-256 931d8c15c8936172…

MALICIOUS

PDF

74.9 KB Created: 2021-09-01 10:46:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: b41141b1475b59b0c30336085c51bbb5 SHA-1: 46f7bea0463d0536f17d87c306d57f8f41b3338f SHA-256: 931d8c15c8936172a14078a99f1947abadd2b1958280dbb497d4247629b55649
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as a phishing trojan. It contains numerous external links, many pointing to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to redirect users. The ML classifier also strongly indicated maliciousness. While no scripts were explicitly extracted, the PDF structure and heuristic firings suggest it's designed to exploit users by directing them to malicious websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9914

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://grandioso.asia/editor_upload_image/file/90268902714.pdf In PDF document text
    • https://takipcisec.com/calisma2/files/uploads/tabafimesivelatumawasana.pdfIn PDF document text
    • http://makingtheturngolf.com/clients/9/92/925d9bae4ecf380f28dbe0e1390c16eb/File/fisojukusuxufekisunixum.pdfIn PDF document text
    • http://www.viksexteriors.com/wp-content/plugins/formcraft/file-upload/server/content/files/160788b71cd644---zedanukafetobarizazopeziv.pdfIn PDF document text
    • https://diversifiedhumansolutions.com/wp-content/plugins/super-forms/uploads/php/files/fbcfc30946ba893976737aaadc6d71b1/regasosorofujawo.pdfIn PDF document text
    • http://woodsfamilypride.org/clients/2/2c/2c83419adcf4927d74d3defe18342386/File/65076681714.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607c63071ab7e---38208944137.pdfIn PDF document text
    • http://sparan-art.ru/ckfinder/userfiles/files/xazewofoxajorapavinibunag.pdfIn PDF document text
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1612346691c35e---40417029889.pdfIn PDF document text
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b3ac280d91e---xitajozokozinuduloto.pdfIn PDF document text
    • http://wccflooring.com/userfiles/files/23362470949.pdfIn PDF document text
    • https://xn----7sbabak5acz7byau.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/b85f0863b6a5f05d1a5c90e0808374d1/kuwovitafonuxozusexi.pdfIn PDF document text
    • https://xn--z4qq44i.tw/upload/actfiles/ponuda.pdfIn PDF document text
    • https://ecoledesgourmets.com/userfiles/file/90557421078.pdfIn PDF document text
    • https://vienhung.com/webroot/img/files/43433564711.pdfIn PDF document text
    • https://accuratesearch.com/userfiles/file/2619177491.pdfIn PDF document text
    • https://michaels-limo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a31718d2049---71526599527.pdfIn PDF document text
    • http://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a6d5dce3a8---78320554841.pdfIn PDF document text
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b4cf2565b6---daduta.pdfIn PDF document text
    • http://185.33.116.145/~acus01/upload/files/58280352876.pdfPDF link annotation
    • https://biserica-izvorul-tamaduirii.ro/files/64708990644.pdfIn PDF document text
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/16070159e4e8c2---sofusegewigijibuxipipu.pdfIn PDF document text
    • http://hevolta.com/upload/file/liwebejebulovilisubovujaf.pdfIn PDF document text
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a3ba107599---bovomalodevenero.pdfIn PDF document text
    • https://essaidafm.com/uploads/FCK_files/file/kosoxokazepapojugokiwuni.pdfIn PDF document text
    • https://didacostruzioni.it/userfiles/file/85988536084.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=going+to+buy+a+book+class+4+questions+and+answersPDF 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_off0000c006.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC006 16808 bytes
SHA-256: a45000215b2e414f6d4f2bb6e40ae2b15da858f6e6b854a984f4ce6173575472
font_01_sfnt_off0000eaf5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAF5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001030c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1030C 11340 bytes
SHA-256: f422c5257e8a627e9756e945435bbda89c4f24ee94eeb8ef5982e9b723e7ab9f