Malicious PDF — malware analysis report

Static analysis result for SHA-256 25ce577eb468bf31…

MALICIOUS

PDF

88.5 KB Created: 2021-03-31 07:05:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: a3dee88a6e5a10e230c0a85a6eb7808c SHA-1: bd69079654801e2ecb7987bdea0aa7f55c19e545 SHA-256: 25ce577eb468bf31175d1ff5edcb3385d01242c5de5e7424025c0b24a719a38b
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, specifically as a phishing or trojan. It contains a large number of external links, forming a link farm, with the primary URL being `https://dafemum.ru/wix?keyword=osrs+f2p+pure+guide`. The document body is heavily obfuscated and appears to be junk data, suggesting the malicious intent is not conveyed through readable text but rather through the embedded links and the file's structure. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://dafemum.ru/wix?keyword=osrs+f2p+pure+guide
    • https://static.s123-cdn-static.com/uploads/4382209/normal_5ffcb2176f660.pdf
    • https://static.s123-cdn-static.com/uploads/4392868/normal_5ff3b1fa07b17.pdf
    • https://cdn-cms.f-static.net/uploads/4448539/normal_601b7828a7f53.pdf
    • https://loseseseveru.weebly.com/uploads/1/3/0/8/130813975/sewuwub.pdf
    • https://kifosaxuwaf.weebly.com/uploads/1/3/4/0/134016965/3944906.pdf
    • https://static.s123-cdn-static.com/uploads/4449618/normal_5ffdc41d8bee9.pdf
    • https://rutuwupu.weebly.com/uploads/1/3/1/3/131378820/futabazivitiguk.pdf
    • https://pefobasor.weebly.com/uploads/1/3/4/1/134131397/4caaa842fde6fee.pdf
    • http://stakingyfi.com/mcgraw_hill_connect_managerial_accounting_answers_chapter_4zy133.pdf
    • https://cdn-cms.f-static.net/uploads/4426550/normal_603cea920efbe.pdf
    • https://xadokefaxigewaj.weebly.com/uploads/1/3/4/3/134314424/ranigateli.pdf
    • https://cdn-cms.f-static.net/uploads/4475586/normal_6059836181c89.pdf
    • https://cdn-cms.f-static.net/uploads/4490121/normal_60302d3462d4b.pdf
    • https://gasimela.weebly.com/uploads/1/3/1/3/131398285/degomixedakib_guduroxa_piremilewop.pdf
    • https://gopopozemilin.weebly.com/uploads/1/3/0/8/130874381/zemezitesamo-gabegogene-kugutorejogi-sutuvugatujid.pdf
    • http://allieshouseofhope.com/mugexidujusefagiduzewova5t75e.pdf
    • https://cdn-cms.f-static.net/uploads/4453719/normal_6047923f37cac.pdf
    • https://tagalevef.weebly.com/uploads/1/3/0/8/130815582/1965369.pdf
    • https://xuvasilibozin.weebly.com/uploads/1/3/5/3/135335949/kekaviwatizev.pdf
    • https://xejinifinedi.weebly.com/uploads/1/3/5/3/135305438/tasubulinegi-basifelewax-bewesa.pdf
    • https://static.s123-cdn-static.com/uploads/4418170/normal_5fc5b84fdb53d.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00011d7a.bin
b66d7f3d34a250c4d1e2a1083403c78bf4afa9043e2cdc0a3f81e2a2036ea71c
pdf-font-stream PDF embedded font (sfnt) at offset 0x11D7A 5124 bytes
font_01_sfnt_off00012efd.bin
59bbf627439c049d5e59be98a38bead1978d8ddc20c363a2aed24acf5e7bc6fa
pdf-font-stream PDF embedded font (sfnt) at offset 0x12EFD 11164 bytes