Malicious PDF — malware analysis report

Static analysis result for SHA-256 a55d547447ff8f82…

MALICIOUS

PDF

82.0 KB Created: 2021-09-23 10:53:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 66dd44670bcb81c365296892168eedc7 SHA-1: 64a4332e2c1c6e4d50ebe4db271826c562a091e3 SHA-256: a55d547447ff8f824ac0a8813632b1fba36121f35498f9ce851c11cc9ffe7586
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many embedded URLs pointing to potentially compromised websites or disposable hosting. The primary attack pattern involves luring users to these external sites, which could host phishing content or serve as a distribution point for further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://lesbambousbleus.fr/ckeditor/upload/files/voduvapem.pdf
    • http://joesservicecenternj.com/userfiles/files/74474071218.pdf
    • https://hsse.cl/files/bexusosikap.pdf
    • https://akilanews.com/ckfinder/userfiles/files/88911035327.pdf
    • http://panziofabian.hu/fck_kepek/79915622448.pdf
    • https://rawoctane.com/uploads/file/54817260754.pdf
    • https://kotypsy.pl/ckfinder/userfiles/files/70535833048.pdf
    • http://esebtekstil.com/resimler/files/gizoxatezulokadewe.pdf
    • http://www.cottagegrad.ru/files/file/86355749481.pdf
    • http://80tner.friend-match.com/upload/files/dugodotegimu.pdf
    • https://bibonatura.hu/ckfinder/userfiles/files/18579139570.pdf
    • https://vongtaytramhuong.vn/upload/files/63586496452.pdf
    • http://chetaomaynganhnhua.com/uploads/files/38039449249.pdf
    • http://purplebyanki-com.bvirani.com/ckfinder/userfiles/files/modutominenuxelujubanisi.pdf
    • http://xn--b1adbbbaeqjtsflbfms0e.xn--p1ai/pict/file/pudiwufuwoset.pdf
    • http://zatuchlina.cz/upload/file/9097042052.pdf
    • http://computerdoki.hu/user/file/85067588976.pdf
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/0dbd18d16643c9914c9911b1340ea13b/xunuduwogofikaguzix.pdf
    • https://yidinfo.net/wp-content/plugins/super-forms/uploads/php/files/4masig1314s4eipdlv3jh27p2h/zusinezunijasox.pdf
    • http://reckdance.pl/userfiles/file/gozibupezi.pdf
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/161466b8d3d784---14398645328.pdf
    • http://ipjanah.ir/wp-content/plugins/super-forms/uploads/php/files/d5uepgabig9chfpequr84pm7h1/79868227360.pdf
    • https://brothers-music.com/ckfinder/userfiles/files/widariwe.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=greek+roman+culture
    • 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_off0000da52.bin
ed5d2bc0d00b22cec37843a4617f2d1006e393fe0e8e0db172ad8c8c5b47a96b
pdf-font-stream PDF embedded font (sfnt) at offset 0xDA52 18956 bytes
font_01_sfnt_off00010b2b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B2B 16792 bytes
font_02_sfnt_off00012342.bin
8112d972edcd0997d2db507a31eb031e2aa6decc2d82be9f3bcd308bac8d4e1e
pdf-font-stream PDF embedded font (sfnt) at offset 0x12342 10364 bytes