Malicious PDF — malware analysis report

Static analysis result for SHA-256 77e491058e2568f3…

MALICIOUS

PDF

109.0 KB Created: 2021-06-25 12:49:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: de74d2fbfebbbbda4fceec2b7b8bb9cd SHA-1: 623ee295cbe2c2a0ac895a4f6bc72105394f8266 SHA-256: 77e491058e2568f3f06e5fdfce548c7f5e3e042d22d4405c75d17b8be31da3a8
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged as malicious by a machine learning classifier and ClamAV, indicating it is likely a phishing or trojan delivery mechanism. The heuristics reveal it functions as a link farm, directing users to compromised WordPress upload storage, which in turn hosts further malicious PDFs. The presence of external URIs and a link farm on disposable hosting further supports a malicious intent to distribute malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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
  • 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://irlanc.ru/uplcv?utm_term=acceptance+and+commitment+therapy+defusion
    • https://gmonlinestore.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a4a5182fde---17893531593.pdf
    • http://www.studiolegalefusimorelli.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bfbd23c6b30---gefogajojo.pdf
    • http://www.cheapmotorcycleinsurancepa.com/wp-content/plugins/super-forms/uploads/php/files/lkrf5tvf8jbukapikp4cru3vd0/gemojufagovemimurewa.pdf
    • http://sl1971.com/clients/5/51/517263f0417f9379c67e6eba0e0bdfe8/File/gotiwera.pdf
    • https://daaeportrett.no/upload/file/lasel.pdf
    • http://dallassymphonyleague.com/clients/1/14/14bb4a025281f1a32078cb68571f7cf3/File/devozikuwavikur.pdf
    • https://aduanaldelvalle.com/userfiles/file/81962022036.pdf
    • https://ceral.pl/ceral/pliki/file/vataxifa.pdf
    • https://hanahana.vn/media/ftp/file/15291221099.pdf
    • http://rogo-rotterdam.nl/files/34806763656.pdf
    • http://bogelaipigeon.com/upload/file/80380054658.pdf
    • https://vishalahospitality.com/ckfinder/userfiles/files/86864993208.pdf
    • https://robertmatzuzi-massagetherapist.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160affccf8304a---41032646742.pdf
    • https://choiceenergynetwork.com/wp-content/plugins/super-forms/uploads/php/files/12db28a47aaf90013b24692120d6a60b/sekaxelaf.pdf
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/160717574a1f1a---dopej.pdf
    • http://accurateverdicts.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c281ddccee6---gawudejimowogewanuvoj.pdf
    • https://www.ideakliniksisli.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c53d1c52660---86232382968.pdf
    • https://ecoinkworld.com/wp-content/plugins/super-forms/uploads/php/files/bb6cb496c256050a4d6f26d35f26e07b/39139552720.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_off00014349.bin
0fb6589ec269ef1bf61836794f88027333d174fa4cf99df0282561e5ec11e604
pdf-font-stream PDF embedded font (sfnt) at offset 0x14349 19176 bytes
font_01_sfnt_off000173d0.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x173D0 16792 bytes
font_02_sfnt_off00018be7.bin
28408520a51e444c7d926bbcd69103c8f75a0c401dd7ce6de5b22a81c087b186
pdf-font-stream PDF embedded font (sfnt) at offset 0x18BE7 11032 bytes