Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8768a876ad9f2e3…

MALICIOUS

PDF

70.7 KB Created: 2021-01-17 15:47:11 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: de09fa7931354271892f92264b0da50b SHA-1: d831de19affc6b37f72a49b3396c3ee14ea9fc79 SHA-256: b8768a876ad9f2e3ab03ad129b46c8642b7cdc540f87e2169b32dadb938ce8a1
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by a machine learning classifier and ClamAV, with heuristics indicating it contains a large number of external links, characteristic of a link farm. The presence of embedded URLs and the PDF_SEO_LINK_FARM heuristic suggest the primary goal is to direct users to potentially malicious or SEO-manipulated external sites. No scripts were extracted, but the PDF structure itself facilitates the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://trafffi.ru/aws?utm_term=gain+dryer+sheets+sds
    • https://vivexizakodol.weebly.com/uploads/1/3/1/4/131483194/roloxokal.pdf
    • https://cdn.sqhk.co/vaminika/Xapehjb/meaning_of_idiom_jump_over_the_broomstick.pdf
    • https://cdn.sqhk.co/gasubapo/whhBjih/ditilonulixemalalikud.pdf
    • https://site-1166675.mozfiles.com/files/1166675/tibunawoduje.pdf
    • https://cdn.sqhk.co/fosasukenum/J83WXjf/real_racing_3_pc_gameplay.pdf
    • https://cdn.sqhk.co/gafisasiwu/giQhhgf/moto_traffic_race_2_mod_apk_hack.pdf
    • https://cdn.sqhk.co/jowapezo/giJgfAU/furogugimeli.pdf
    • https://cdn.sqhk.co/niwonosorude/fiagehe/8_day_jump_start_metabolism_diet.pdf
    • https://cdn.sqhk.co/malofavu/djbijhj/cute_hashtags_for_snapchat_dog_filter.pdf
    • https://cdn.sqhk.co/xobanozizesa/3iahidi/jimugawonenevanerunibigo.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/legenapi/bts_love_yourself_answer_album_buy_online.pdf
    • https://s3.amazonaws.com/jadudusujuje/38396024578.pdf
    • https://s3.amazonaws.com/dosalapasenow/kitonudisuk.pdf
    • https://s3.amazonaws.com/patotale/elton_john_columbia_sc.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://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d901.bin
fed8e227902a7f22a8f4be350d48fdb8a776950862ce79939e0c29dbe03351ff
pdf-font-stream PDF embedded font (sfnt) at offset 0xD901 5016 bytes
font_01_sfnt_off0000ea11.bin
fd98d021364b0ee0dd126e604990228a84b697dfde96d6d08fa3aab8eabeb0bf
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA11 10620 bytes