Malicious PDF — malware analysis report

Static analysis result for SHA-256 17fcd9ea76419c26…

MALICIOUS

PDF

86.7 KB Created: 2021-02-21 02:57:26 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 8f454e294988fd0804e8d0f712325fa2 SHA-1: ca5d4d9179f472f529be026a4d1933d0d9e6616d SHA-256: 17fcd9ea76419c265df2ff21a76bba22dd1caedfbe4d592ef89377be4bc4abe4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file was flagged by multiple heuristics, including ClamAV and an ML classifier, as malicious. It contains a large number of external links, many of which are likely part of a link farm or SEO manipulation scheme. One of the primary URLs identified is https://druttle.ru/strik?utm_term=singer+sewing+machine+froze+up, which is suspicious due to its structure and domain. The presence of embedded JavaScript, though not explicitly detailed in the provided evidence, is a common method for executing malicious actions within PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

Heuristics 5

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://druttle.ru/strik?utm_term=singer+sewing+machine+froze+up
    • http://benosetib.iblogger.org/zoxegodekukipete.pdf
    • https://cdn-cms.f-static.net/uploads/4420905/normal_5fe900cba589d.pdf
    • https://diwowure.weebly.com/uploads/1/3/4/5/134592565/5356967.pdf
    • https://static.s123-cdn-static.com/uploads/4380403/normal_5fffc679a68aa.pdf
    • https://static.s123-cdn-static.com/uploads/4454684/normal_5ffa4555e9906.pdf
    • https://static.s123-cdn-static.com/uploads/4417652/normal_5fe599b964b83.pdf
    • https://zaduguwage.weebly.com/uploads/1/3/0/8/130874015/1469183.pdf
    • https://static.s123-cdn-static.com/uploads/4486365/normal_5fc90b256c663.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.daltonmaag.com/
    • https://s3.amazonaws.com/sorapobuk/estilo_de_aprendizaje_activo.pdf
    • https://s3.amazonaws.com/zalomi/an_autobiography_of_a_yogi_malayalam.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://scripts.sil.org/OFL

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000107e1.bin
57bcc0f0673224dfa1b249b83ec6cf051917358d8d35112e7a492224c83c2606
pdf-font-stream PDF embedded font (sfnt) at offset 0x107E1 5444 bytes
font_01_sfnt_off00011a46.bin
fa366705987eb352857b228b91cba156c43f5907fa21dfceba0952cab2a7601f
pdf-font-stream PDF embedded font (sfnt) at offset 0x11A46 11000 bytes
font_02_sfnt_off00013fb8.bin
d1f4a20f0e35a0564be54678b929bb8c711862c507f070c2b9a6abea8daf4378
pdf-font-stream PDF embedded font (sfnt) at offset 0x13FB8 4324 bytes