Malicious PDF — malware analysis report

Static analysis result for SHA-256 1b6316b4c7de2580…

MALICIOUS

PDF

109.7 KB Created: 2021-05-06 05:17:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 3af517a9cbad6fcd4efe2ce0e1c4bbfa SHA-1: e53b1a753c96eeebf0a6a982aafd1f4c52bb2a13 SHA-256: 1b6316b4c7de25802a4de7fc6875a81d0228c27f5cd2c59ae28d8f647ba4f089
186 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as a link farm and by a machine learning classifier as malicious. It contains numerous external URLs, many hosted on disposable domains, suggesting a phishing or SEO spam campaign. ClamAV also detected it as Pdf.Phishing.Trojan. No scripts were extracted, but the PDF structure itself is indicative of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • 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
  • 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://dugedepap.ru/strik?utm_term=pretty+little+liars+novel+amazon
    • https://cdn.sqhk.co/kigaratak/jgijIzN/65948983304.pdf
    • https://cdn.sqhk.co/jisokemefaz/lrJriez/punebadoxojoduzijibujuto.pdf
    • https://cdn.sqhk.co/japexexuko/u6icHUt/15991174533.pdf
    • https://jobeluraxofedir.weebly.com/uploads/1/3/4/3/134317239/wirejigul.pdf
    • https://jesaguxofugu.weebly.com/uploads/1/3/4/6/134659129/4379478.pdf
    • https://kinumefiboposif.weebly.com/uploads/1/3/4/8/134865532/sugilidubipo.pdf
    • https://mukekevujawova.weebly.com/uploads/1/3/0/9/130969498/bb22960b6492.pdf
    • https://vasinurevesodux.weebly.com/uploads/1/3/4/6/134605286/gapukujebi_faguvurab_rapifudabetuja.pdf
    • https://cdn.sqhk.co/wumidimux/oEjaihu/15637328274.pdf
    • https://cdn.sqhk.co/bupewazadufa/Snja7jf/temple_run_2_cool_math_games.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.daltonmaag.com/
    • https://s3.amazonaws.com/banula/revolutionary_suicide_summary.pdf
    • https://3175e58c-9db9-4d87-bcb9-15e03531d93d.filesusr.com/ugd/c93210_93627fe51f9545b595cd3ef178a27677.pdf?index=true
    • https://3c4962d9-41f7-4f14-8396-dad57cc8de20.filesusr.com/ugd/a2de88_ba14e1213c9d442d9030f6233f2cc3b2.pdf?index=true
    • https://s3.amazonaws.com/suzujewa/jio_tv_apps_free_apk.pdf
    • https://uploads.strikinglycdn.com/files/d9d00e2a-abdd-45d9-9aa0-b33f9cb240bd/dragon_ball_manga_for_sale.pdf
    • https://uploads.strikinglycdn.com/files/70661de7-2d83-4098-8617-712c0adcfda4/91896328821.pdf
    • https://uploads.strikinglycdn.com/files/98ffdd39-b6f7-4848-8445-a094d63c8c01/does_the_city_of_babylon_still_exist.pdf
    • https://uploads.strikinglycdn.com/files/9a1def75-be6e-43fb-863d-9703f9782815/sujilipobufugi.pdf
    • https://s3.amazonaws.com/dosalapasenow/76183377162.pdf
    • https://b47237a6-1880-4d87-9598-f01162bab054.filesusr.com/ugd/1fe0ea_b857a82c98274f90915d04dbb7405a5f.pdf?index=true
    • https://04934832-22f3-474e-96de-b9d593e92251.filesusr.com/ugd/f390e7_d78de84dce044764a4831b1de6f75102.pdf?index=true
    • https://ac4cd5cf-e861-4b1b-a585-e47049f737a6.filesusr.com/ugd/843280_3f986687e29c4be3877219681e9f5105.pdf?index=true
    • https://uploads.strikinglycdn.com/files/5df848d0-f0aa-4932-b98e-04b9c6867489/pretty_little_liars_season_4_episode_13_full_episode.pdf
    • https://a1bd7baf-2de3-4c81-8914-4b74a732ecf9.filesusr.com/ugd/c89f15_d96f77708ba2462793e175a49bd8ef37.pdf?index=true
    • https://3c3b6f52-20a2-448a-be11-eec5930c502f.filesusr.com/ugd/0ca786_bb42918b79ce4f909b13c1b5b3f7fd74.pdf?index=true
    • https://39472683-7d43-4bc3-882b-0947a83fd973.filesusr.com/ugd/544c7e_caf5e3c2347f4e2e9f62ab461fb537f5.pdf?index=true
    • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00015fd7.bin
d0fbd0ab7fd4bfe9e4c8b36217a18ed6b76cd92ff15b1e3aab131adb90b99e73
pdf-font-stream PDF embedded font (sfnt) at offset 0x15FD7 4832 bytes
font_01_sfnt_off00017031.bin
b39057d4eb720b203a7224f0f0dd1b51b302c430483298964c33ab57fc0145f7
pdf-font-stream PDF embedded font (sfnt) at offset 0x17031 12624 bytes
font_02_sfnt_off00019b1b.bin
0d0f64e27578eb124b8bc81c7eceacdd166e22eddd95c81328e9fbd7de2a6333
pdf-font-stream PDF embedded font (sfnt) at offset 0x19B1B 4324 bytes