Malicious PDF — malware analysis report

Static analysis result for SHA-256 8450ea2331b77f53…

MALICIOUS

PDF

84.1 KB Created: 2021-06-12 01:12:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 34f6670579680230b5a9b49b6e713de8 SHA-1: c507581cb6bdd135a69d9d56394eaa94ab2b736c SHA-256: 8450ea2331b77f536aaa14cc73dbd0a0b5282fd484c5f824f0c6f8c9ca157c4e
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many hosted on compromised WordPress sites, suggesting a link farm or phishing lure. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body, though heavily obfuscated, contains text related to an 'answer key', reinforcing the lure. No scripts were extracted, but the PDF structure itself facilitates redirection to malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 https://allytemp.ru/uplcv?utm_term=real+world+lab+locating+an+epicenter+answer+key PDF link annotation
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/1609a55a0e8f92---58882618928.pdfIn PDF document text
    • http://www.aluvascientific.com/UserFiles/file/47601708137.pdfIn PDF document text
    • http://finsura-lifedirect.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607734e35bf72---midetuseribixekazezu.pdfIn PDF document text
    • http://popnmusic.fr/userfiles/file/40927059347.pdfIn PDF document text
    • https://yucekalipmakina.com/tsrm1/img/userfiles/file/81743648352.pdfIn PDF document text
    • http://cpils.com/userfiles/file/siwetediwologoroxejar.pdfIn PDF document text
    • http://progfin.pl/userfiles/file/84750663857.pdfIn PDF document text
    • http://kibbkw.com/uploads/file/71687298145.pdfIn PDF document text
    • https://www.truesdalepainting.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c4e6df0056---futobovita.pdfIn PDF document text
    • http://chnli.tw/CKEdit/upload/files/savibomugudejoxepuzog.pdfIn PDF document text
    • http://playeasypiano.com/resources/fck_images/pusagafejazuwemaniwive.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7a84f6cf24---gevaguxerarefafewosi.pdfIn PDF document text
    • https://www.americanapi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d6ed8db1af---sixegetulovezutogoken.pdfIn PDF document text
    • http://wbbray.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078fa23dcbdc---zepalibusafez.pdfIn PDF document text
    • http://www.pointcookelectrician.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb16b737c7---71640484425.pdfIn PDF document text
    • http://springhs1988.com/clients/a/a7/a70db2535ed58991dd9724faf9b165d0/File/76520121165.pdfIn PDF document text
    • https://vmwarts.com/ecovic/file/62711270329.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f5b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5B1 5648 bytes
SHA-256: 031bc7400a15651f525ac7b9976f345c4adf9703d5ea375cbf4e939f01372f74
font_01_sfnt_off0001090f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1090F 10720 bytes
SHA-256: b3a65fa01c0c7e2282da9be0780c5ee24255c837fd79dcad20e77ccdd2aec55b
font_02_sfnt_off00012dbb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DBB 16204 bytes
SHA-256: c988415812f594187b0a0ed75dc52802e798e1695b49bd300f8412a65040a449