Malicious PDF — malware analysis report

Static analysis result for SHA-256 44e60bd0c920e070…

MALICIOUS

PDF

92.2 KB Created: 2021-03-25 11:58:54 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-22
MD5: 09cb2f08867dabde558c49545ae57d73 SHA-1: 7825a61fafeb1b32171145cea306a165f7747212 SHA-256: 44e60bd0c920e070cfdd7bcceb763979e70ce965b484751379b228bbd6953c03
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, identified as a link farm, with many hosted on disposable domains. This behavior, combined with ML and ClamAV detections, strongly suggests a malicious intent, likely to distribute further malware or engage in phishing. The document body itself is heavily obfuscated and contains metadata from wkhtmltopdf, indicating it was likely generated programmatically to host these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://druttle.ru/award?keyword=alkalosis+respiratory+pdf PDF link annotation
    • https://cdn.sqhk.co/gudopokobipa/mgembgc/jiwetijifoni.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4413590/normal_5fff839c51c82.pdfIn PDF document text
    • https://cdn.sqhk.co/soxuvezosapa/gcs49QB/dark_legends_pack_yugioh.pdfIn PDF document text
    • http://nubemeketetu.mypressonline.com/91571279721.pdfIn PDF document text
    • https://cdn.sqhk.co/feketukadoz/cpmLKTO/69921286587.pdfIn PDF document text
    • http://suzamajotibe.mywebcommunity.org/78801612817.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4454163/normal_6057b47f75a28.pdfIn PDF document text
    • https://cdn.sqhk.co/xibexowufifu/oifefjc/skiena_algorithm_design_manual_review.pdfIn PDF document text
    • https://cdn.sqhk.co/wopidevepip/Wicjaig/homemade_chocolate_ice_cream_recipe_without_machine.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4498330/normal_601cbab45d9c1.pdfIn PDF document text
    • https://toxafowusolele.weebly.com/uploads/1/3/2/8/132815148/fuwepiw_sovobak_legipore.pdfIn PDF document text
    • http://tozaworewinox.mywebcommunity.org/why_was_the_affordable_care_act_needed.pdfIn PDF document text
    • https://vuwurata.weebly.com/uploads/1/3/4/4/134481670/0c0c29b6.pdfIn PDF document text
    • https://cdn.sqhk.co/wesuwajil/Wuhdpid/10391435297.pdfIn PDF document text
    • https://pasuwuzo.weebly.com/uploads/1/3/1/4/131438486/dufibinave.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4492574/normal_6025d556acafd.pdfIn PDF document text
    • https://cdn.sqhk.co/pajijolabalu/f2Hhegf/xozogisovegud.pdfIn PDF document text
    • https://cdn.sqhk.co/puvivefujef/fie1xDX/icd_10_guidelines_for_myocardial_infarction.pdfIn PDF document text
    • https://cdn.sqhk.co/rojarimeg/hdhiljQ/tixowa.pdfIn PDF document text
    • http://fijexojor.getenjoyment.net/dusupew.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • http://zegiwewezenaro.myartsonline.com/total_body_works_5000_exercise_chart.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010983.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10983 4872 bytes
SHA-256: 94e956d36d630e1d0706d8e39bbc67012881d4c812e61a0c57c78b2f00b964fa
font_01_sfnt_off00011a31.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A31 10704 bytes
SHA-256: 445c3eaf988dc027c67b91e50e3e6f6122a93c2286b4711c7bcc75fc5a8ff19d
font_02_sfnt_off00013edf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13EDF 16296 bytes
SHA-256: 829e7474847e956eb8b98a1f1cb6b2aafc773cbccfbc9edcf1a26e6d49dc9c58
font_03_sfnt_off0001547e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1547E 4324 bytes
SHA-256: 1062cd8ddf90f4344fa193b395386d5669df1a952e5759311ca261a71931f361