Malicious PDF — malware analysis report

Static analysis result for SHA-256 1f330c2bfc3d81d6…

MALICIOUS

PDF

109.7 KB Created: 2021-04-07 05:22:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 4251f4289b7055cb6448b03a4d4f1596 SHA-1: c8c575a651efbf3c0a9e986ff3b8b840422748cd SHA-256: 1f330c2bfc3d81d6f5cb55692a2c84cc3861de07e0d656d0b0ab8db5f3d3765f
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics, including ClamAV and an ML classifier, as malicious. It contains a large number of external links, many of which point to PDF files hosted on suspicious domains, suggesting a link farm or redirection scheme. The document body, though heavily obfuscated, appears to be related to search engine optimization for academic papers, likely a lure to encourage clicks on the embedded malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9782

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-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://lozipotod.ru/award?keyword=higher+engineering+mathematics+by+bv+ramana+pdf
    • https://cdn.sqhk.co/kuwusemob/D8ifij3/27208998277.pdf
    • https://cdn.sqhk.co/telapunojawu/gCigWih/35207306447.pdf
    • https://cdn.sqhk.co/rujiwujik/dJ8Eifw/61229187542.pdf
    • https://cdn-cms.f-static.net/uploads/4403565/normal_5fe8af68caa50.pdf
    • https://cdn.sqhk.co/ketegobuto/lgBfXbs/91868624761.pdf
    • https://cdn.sqhk.co/tezesafura/gfinDwN/vidufigorijovifinanasedo.pdf
    • https://static.s123-cdn-static.com/uploads/4426072/normal_5fca4749aac43.pdf
    • https://cdn.sqhk.co/kesavaki/jcTJjb8/74673188903.pdf
    • https://cdn.sqhk.co/pojimisuso/exgiM2o/relilisazusuvasusew.pdf
    • https://cdn-cms.f-static.net/uploads/4365547/normal_6009c369baf67.pdf
    • https://cdn.sqhk.co/didowolikex/jjbgc6W/descent_road_to_legend_side_quests.pdf
    • https://static.s123-cdn-static.com/uploads/4476285/normal_5fc85e48e40b0.pdf
    • https://cdn.sqhk.co/zimidenex/jgIzij1/53457916112.pdf
    • https://cdn.sqhk.co/fomolunuvufa/ifrBHge/snapchat_login_help.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://smc.org.in)MeeraRegularMeera2016SMC7.0.0+20171102Hussain
    • http://smc.org.inhttp://smc.org.in
    • http://fedorahosted.org/lohit
    • http://www.opentle.org
    • https://uploads.strikinglycdn.com/files/7e2da56d-5c86-47e9-898c-bcd3dd840674/kenworth_t270_owners_manual.pdf
    • https://s3.amazonaws.com/jojitagifuva/ambient_sound_app.pdf
    • https://uploads.strikinglycdn.com/files/3665e6b9-b627-4a00-8dc6-61ab20f73c98/vurupovulopaxasidefoxanuf.pdf
    • https://s3.amazonaws.com/ditiruz/what_is_the_difference_between_plan_elevation_and_section.pdf
    • https://0a497e50-07dd-462d-832d-d8678f741a8e.filesusr.com/ugd/5f857b_ba1796b292df4d149a1fb8a7075a1bea.pdf?index=true
    • https://s3.amazonaws.com/salosibejodod/1706853444.pdf
    • https://badbb018-ab4e-499b-b788-960949b82e3d.filesusr.com/ugd/4f4c56_20f4fc759bf84df1a18440d8e618e7eb.pdf?index=true
    • https://s3.amazonaws.com/vifusupegiza/tajusiluwagudekerimerov.pdf
    • https://s3.amazonaws.com/runuzitexokol/bilindar_kannada_film_songs.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://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License
    • http://scripts.sil.org/OFL
    • https://gitlab.com/smc/meera/blob/master/COPYING
    • http://www.gnu.org/licenses/gpl.html

Extracted artifacts 8

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_009_off00018aba.bin
de67dac77e71aeca5b22e3f14b3a693231f93498e2a41f6a297bab5d1def4fe8
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x18ABA 17408 bytes
font_00_sfnt_off0001014d.bin
7ca3f79237f0268976f0874141738179710a8d6d580de97ebc05b15337efb780
pdf-font-stream PDF embedded font (sfnt) at offset 0x1014D 4032 bytes
font_01_sfnt_off00010fc7.bin
3ab4a8244da863dacc050bb31fbb572ccd30222d7fb5caa37a2f66ca1b9caa3a
pdf-font-stream PDF embedded font (sfnt) at offset 0x10FC7 5800 bytes
font_02_sfnt_off00012358.bin
e23308bb06bff427f4fe2d795198e016b2e9db23d45fd702446b15ef1a1323d1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12358 3048 bytes
font_03_sfnt_off00012f63.bin
1b559382ed6243dbaf0ffe4b5bcf35fbbbfd695520fd9f854e37b3fe7f47daf2
pdf-font-stream PDF embedded font (sfnt) at offset 0x12F63 3664 bytes
font_04_sfnt_off00013e19.bin
0b38f6fd5e0b54bfa22d5adee1cfe00629fe134100fc7cfc1ad14a2ab7974207
pdf-font-stream PDF embedded font (sfnt) at offset 0x13E19 6148 bytes
font_05_sfnt_off00014df1.bin
dfc6b912628a0cfd78a854c4552d4b63834b5266094acd967c7753fbc39207c8
pdf-font-stream PDF embedded font (sfnt) at offset 0x14DF1 2484 bytes
font_06_sfnt_off000158e4.bin
23dbfc11174231af61c3d835c88bcc7c2ccea6e3d7c47b70fe9602633547f48e
pdf-font-stream PDF embedded font (sfnt) at offset 0x158E4 17500 bytes