Malicious PDF — malware analysis report

Static analysis result for SHA-256 8bc21a4be4c8a8d0…

MALICIOUS

PDF

76.7 KB Created: 2021-09-06 01:21:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 68bc02b778eed499bc721fbf2f909b54 SHA-1: 6259c45b913788bfb3d2581afc3df36aa2caada2 SHA-256: 8bc21a4be4c8a8d0f3552c8066223f27cab64a0c7496d4e7d65cc200e19ddf8e
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ML classifiers and ClamAV, and exhibits characteristics of a link farm pointing to compromised CMS uploads. The heuristic 'SE_INVOICE_LURE' suggests the document's content is designed to trick users into clicking embedded links, which are numerous and spread across various domains. Although no scripts were explicitly extracted, the PDF format itself can embed JavaScript, and the overall structure points towards a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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.
  • Fake invoice / payment lure low SE_INVOICE_LURE
    Document contains invoice or payment language paired with an action verb — useful context when combined with link, macro, or attachment indicators
  • 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://abacusnancy.com/userfiles/file/93187505772.pdf
    • http://focostrade.com/files/20210611073629.pdf
    • http://archgeo-leszno.pl/uploads/userfiles/files/mepujaxalilutedumaxadav.pdf
    • http://moyamoya.center/images/hand_uploaded/files/26652108315.pdf
    • http://andreagarciam.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e17ab2e1309---84811852580.pdf
    • http://www.louthadventures.ie/wp-content/plugins/formcraft/file-upload/server/content/files/160b894a48b250---44279099203.pdf
    • https://christembassyromford.org/wp-content/plugins/super-forms/uploads/php/files/80384fde319e3eb6b98cfcb4c07a6b97/12711359047.pdf
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16099cd54cc07a---kekelenijafawewiratibokab.pdf
    • https://edu-mate.kr/_UploadFile/Images/file/27227106578.pdf
    • http://rosesrealtyhomes.com/userfiles/files/84360886465.pdf
    • http://youngshiny.com/userfiles/file/1628544311.pdf
    • http://madmojo.com/fckupload/file/sawidujadisep.pdf
    • https://hocaukhudothithanhphogiaoluu.com/asset/site/files/bebumib.pdf
    • http://nc2e.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160bb8205895b1---baxenezur.pdf
    • http://ybshajiang.com/userfiles/file/2021-07-25/2107252212560973157g6gv2m6ltwh.pdf
    • https://www.3dreamchurch.com/wp-content/plugins/super-forms/uploads/php/files/3e14ada8e46e778ee04f163f1502d735/wenesilek.pdf
    • https://alatheir.com/atheirwsfiles/file/770398542.pdf
    • https://afriqueitnews.com/wp-content/plugins/super-forms/uploads/php/files/7faed232e723b7447eb15b7af01c993a/73850099417.pdf
    • http://f-okinawa.com/img/tmp/files/44415056277.pdf
    • https://hankilfood.com/upfile/files/zinutabuvenasuvufobabeki.pdf
    • http://www.siscbolivia.com/admin/uploaded/fck/file/76220289150.pdf
    • https://allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/3c820d74b3e8e68fd37a2a1fc960924d/reviwakazo.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=advantages+of+a+computer+over+a+manual+typewriter
    • 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_off0000c9c4.bin
e496ea0acb7e3f30325f97cc8f681540672ce0b56344aef522308fd16e3866ad
pdf-font-stream PDF embedded font (sfnt) at offset 0xC9C4 16164 bytes
font_01_sfnt_off0000f2e0.bin
743deb3d7a46c8cb36b89d18dc38ca240387e20080073234eafb46578ab9b841
pdf-font-stream PDF embedded font (sfnt) at offset 0xF2E0 11312 bytes
font_02_sfnt_off00010d5f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10D5F 16792 bytes