Malicious PDF — malware analysis report

Static analysis result for SHA-256 fe9943b25390028a…

MALICIOUS

PDF

82.1 KB Created: 2021-05-01 21:04:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: af852db34cc6e4cb23f288beb6b76091 SHA-1: df46ec0421d21bc4a6e3d649bad5755474a4697d SHA-256: fe9943b25390028ae23e09f7801b405d410bf071e9b5b4e545c1d3647abaeef6
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript T1203 Exploitation for Client Execution

The PDF contains a link farm with multiple external URLs, including a suspicious domain 'vilenefex.ru', suggesting a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly indicate malicious intent. The document's content, though obfuscated, appears to be a lure related to educational topics to mask its malicious purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • 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://vilenefex.ru/strik?utm_term=ecuaciones+trigonometricas+ejercicios+resueltos+paso+a+paso+pdf PDF link annotation
    • https://cdn.sqhk.co/koxuvusu/xijgKge/linear_pairs_and_vertical_angles_instruction.pdfIn PDF document text
    • https://cdn.sqhk.co/jogepirar/DjjBkje/how_to_change_my_server_location_windows_10.pdfIn PDF document text
    • http://mazejofeg.mygamesonline.org/jubojojejaj.pdfIn PDF document text
    • https://cdn.sqhk.co/xuzizadupu/Wphb3gc/12769380464.pdfIn PDF document text
    • https://cdn.sqhk.co/nasubivapu/jh95jfF/81049398916.pdfIn PDF document text
    • https://cdn.sqhk.co/rufopunuk/LSlifjg/games_like_kick_the_buddy_for_pc.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://c09438b0-f1cf-4ade-afa2-d322e048c450.filesusr.com/ugd/313cc6_c7d16cbc85a44926820041be49fe50f9.pdf?index=trueIn PDF document text
    • https://ca7c05ed-d233-4774-9cf9-08ff86aa6c73.filesusr.com/ugd/b42fd6_3a878d04861c4379a5f2664d37b3f970.pdf?index=trueIn PDF document text
    • https://fb9345b8-40be-4608-a8ff-9c5427dba92f.filesusr.com/ugd/98d639_959a35e0a8604c4586742bba03f1ad7a.pdf?index=trueIn PDF document text
    • https://3176e400-c268-4dc0-8d69-08eae86937f8.filesusr.com/ugd/ea2f88_7fd36a1364fc464ba06ec40c56eff1f0.pdf?index=trueIn PDF document text
    • https://59e5a08b-0d8d-455f-a3a7-35a3b781ab3e.filesusr.com/ugd/784815_a716ddf1127e4bdd8613a4dcc9f6e116.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/jawusawar/70882499466.pdfIn PDF document text
    • https://s3.amazonaws.com/baxegezivumi/giwigiluban.pdfIn PDF document text
    • https://35b1a599-9f45-4897-82ce-59a931fc5495.filesusr.com/ugd/daca0d_09229211177c4ca5939126721ddca79c.pdf?index=trueIn PDF document text
    • https://02bc4616-4eae-4b38-b2c9-0e654f754ee0.filesusr.com/ugd/069df5_21788642abb44959bb4885ca5c7b72a2.pdf?index=trueIn PDF document text
    • http://tirisesu.onlinewebshop.net/rewenonimawodi.pdfIn PDF document text
    • http://fogokenum.onlinewebshop.net/bearing_catalogue.pdfIn PDF document text
    • https://s3.amazonaws.com/legapatatezisa/guvizesuxepatu.pdfIn PDF document text
    • https://484a0fbd-04e0-416f-b335-41eb3f66808b.filesusr.com/ugd/228afb_329b5ded23464659966fa4f366b9f3dd.pdf?index=trueIn PDF document text
    • https://6558ac43-984d-4e3a-97a1-dec8860611ed.filesusr.com/ugd/c73740_2dcf262e21c9488287ef4d6cf902cfd6.pdf?index=trueIn PDF document text
    • https://5e7fdb44-65a6-4d88-9b36-b69c04d36e08.filesusr.com/ugd/b547b4_b8a13350df334015b0c21e1106727520.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/xunilukegez/what_does_the_little_yellow_heart_mean_on_snapchat.pdfIn 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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fdaa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDAA 5508 bytes
SHA-256: 27d6ed0493bd3a1ab7ead6d913e29eced6fbe29781bc969f754e8b3ddd3ecbec
font_01_sfnt_off0001105b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1105B 12320 bytes
SHA-256: 9018501ceda7c3fd33673a257f26ea19778c51a3582aab9e0360d9a25babd542